Current diesel engines are struggling to achieve exhaust emissions regulations margins, in certain cases penalizing the fuel consumption. The exhaust gas recirculation (EGR) continues to be employed as a technique to reduce ...[+]

Current diesel engines are struggling to achieve exhaust emissions regulations margins, in certain cases penalizing the fuel consumption. The exhaust gas recirculation (EGR) continues to be employed as a technique to reduce NOx emissions. EGR dispersion between cylinders is one important issue when a high pressure (HP) loop is used. Different techniques have been developed in order to analyze the EGR dispersion between cylinders in an engine test bench. In this paper a methodology using the in-cylinder pressure was developed. The in-cylinder pressure was used to calculate a heat release law and combustion parameters that were used to analyze the EGR dispersion between cylinders. Engine test measurements at three different engine speeds and with three different HP-EGR configurations were performed in order to assess the developed analysis methodology. NOx emissions and fuel consumption were also compared between the different HP-EGR configurations to complete the analysis. The developed methodology was successfully used in three different operating conditions for three different HP-EGR configurations, showing the relation between the decrease in EGR dispersion between cylinders and the decrease in NOx emissions, while maintaining and, in some points, improving the fuel consumption.[-]